This is a research study being conducted worldwide which will include a total of about 900 men and women, approximately 18 of whom will be enrolled at this site. The purpose of this study is to evaluate the comparative safety and cholesterol lowering of simvastatin 40 and 80 mg/day versus atorvastatin 20, 40, and 80 mg/day, in patients with high cholesterol. The study will use approved doses of atorvastatin 20, 40 and 80 mg/day, as well as approved doses of simvastatin 40 and 80 mg/day. Simvastatin is also known as Zocor, while atorvastatin is known as Lipitor.